Proportional Relationships and Slope: Grade 8 Math Test – PDF Download

Question 1: Unit rate from a table (2 points)

The table shows the cost of grapes. Write an equation for the cost \(y\) of \(x\) pounds, and find the cost of 11 pounds.

Question 2: Graph a proportional equation (3 points)

Consider the equation \(y=\frac{3}{2}x\).

1. Plot two points that satisfy the equation. (1 point)
2. Draw the line. (1 point)
3. State the slope of the line. (1 point)

Question 3: Slope and equation from a graph (2 points)

Find the slope of the line shown and write its equation.

Question 4: Similar triangles and slope (3 points)

Two right triangles are drawn under the same line, as shown.

1. Find the rise of the larger triangle. (1 point)
2. Explain why the slope is the same for both triangles. (2 points)

Question 5: Compare two speeds (3 points)

Car A’s trip is shown in the graph. Car B’s distance is given by \(y=58x\), where \(x\) is hours. Which car is faster, and by how many miles per hour?

Question 6: Slope and intercept (2 points)

For the equation \(y=-\frac{3}{4}x+6\), state the slope and the \(y\)-intercept. Is the relationship proportional? Explain.

Question 7: Points to an equation (2 points)

A line passes through \((-3,5)\) and \((1,-3)\). Find its slope and write its equation in the form \(y=mx+b\).

Question 8: Streaming plan (3 points)

A movie site charges a $5 sign-up fee plus $3 for each movie rented.

1. Write an equation for the total cost \(y\) of renting \(x\) movies. (1 point)
2. Find the cost of 9 movies. (1 point)
3. Ava spent $41. How many movies did she rent? (1 point)

⬇ Download the Grade 8 Proportional Relationships and Slope test (PDF, 82 KB)

See every chapter on the Grade 8 math page.